/**
 * @author: wangjunchao(王俊超)
 * @time: 2019-07-06 20:06
 **/
public class Solution {
    /**
     * <pre>
     * Write an efficient algorithm that searches for a value in an m x n matrix.
     * This matrix has the following properties:
     *
     * Integers in each row are sorted in ascending from left to right.
     * Integers in each column are sorted in ascending from top to bottom.
     * Example:
     *
     * Consider the following matrix:
     *
     * [
     *   [1,   4,  7, 11, 15],
     *   [2,   5,  8, 12, 19],
     *   [3,   6,  9, 16, 22],
     *   [10, 13, 14, 17, 24],
     *   [18, 21, 23, 26, 30]
     * ]
     * Given target = 5, return true.
     *
     * Given target = 20, return false.
     * </pre>
     *
     * @param matrix
     * @param target
     * @return
     */
    public boolean searchMatrix(int[][] matrix, int target) {

        if (matrix == null || matrix.length == 0) {
            return false;
        }

        int i = 0;
        int j = matrix[0].length - 1;
        while (i < matrix.length && j > -1) {
            if (matrix[i][j] == target) {
                return true;
            } else if (target < matrix[i][j]) {
                j--;
            } else {
                i++;
            }
        }

        return false;
    }
}
